Vacuum tube socket



A Dec. 31, 193.15. l' D R. DE TAR A 2,026,420

VACUUM TUBE SOCKET Filed Jan. so, 1951 C @una l inventor' Donald R. DeTar His Attorney Patented Dec. 31, 1935 y VACUUM TUBE SOCKET Donald R. De Tar, Audubon, N.k J., assigner to General Electric Company, a corporation of New York Application January 30, 1931, Serial No. 512,352

4 Claims.

My invention relates to a socket for vacuum tubes or the like apparatus of the type in which a plurality of contact pins or terminals are arranged to engage contact members detachably, and has for its principal object the provision of an improved device of this character which is simple in construction and` eilicient under all with live parts of the socket when inserting the 20 tube therein; loosening or creeping of the tube in the socketor loss of contact between prongs and contacts due to vibration; poor contact or loss of contact due to weakening of the contact springs or to foreign matter on the prongs or the contact elements. In many cases, further, diiculties in manufacture of the socket have been encountered due to complexity of design, the requirement of a multiplicity of riveting or other fastening operations, or the necessity of precise and extremely accurate forming of contact members or other parts to insure adequate and permanent electrical contact ofthese members with the tube prongs.

In accordance with my invention these diiy culties and others of like nature are avoided by 35 the provision of an improved socket for vacuum y tubes or the like comprising contact members held relatively loosely, in position to engage the tube terminals, between a contact supporting and insulating member or molded block having open- 40 ings to receive the electrodes, and a second insulating member having the formof a plate" perforated for the passage of the terminals therethrough, the contact members having .resilient portions disposed within these openings of the 45 supporting member and portions which extend lacross relatively thin outer walls of the openings between an end of these walls and the plate of insulating material. These latter portions of the contact 4members each include a hook-like port. ,n

50 or bend resting on and partially enclosing the above-mentioned end of the thin walls to assist in maintaining the contact members in position in the block before the insertion of theterminals and to prevent the contact portions from being 55 pressed through the openings of the block when the terminals are inserted therein. These bends or hook-like portions are extended outside the boundary of the block to form terminal or circuit connection members disposed radially of the 60 socket.

(Cl. FXS- 328) The contact supporting member and the contact members are so arranged that the tube is held rigidly in position in the socket and the contact members cannot be damaged by inserting the tube at an angle. 5

No live parts are exposed on that side of the socket .from which the tube projects and danger of short circuit resulting from contact of the tube prongs with such parts when inserting the tube in the socket is thereby obviated.

The contact members are so shaped that vibrationv of the socket and tube tends to cause the tube terminals or prongs to creep backl more tightlyn into the socket, thereby making possible the mounting of the tube in a horizontal or other l5 desired position other than* the usual vertical position, or even hanging downwardly from the socket.

In the assembly of the socket the parts are held together by a single rivet or other suitable fastening means connecting the insulating plate to the contact supporting member, thereby retaining the contact members in operating position without further fastening means therefor.v

The proper functioning of the socket does not depend upon exact forming of the contact members or other parts. Therefore, the considerable variation in shape of the contact members which must be tolerated, due to unavoidable variations in the temper of the bronzefrom which these contact members are formed, is permissible without danger of detrimental effects in the operation of the device.

The action of the contact members or springs on the tube terminals or prongs is such as to remove foreign material from the surfaces of these members which are in electrical contact when the tube is in position in the socket.

My invention will be better understood from the following description when considered in connection with the accompanying ydrawing and its scope will be pointed out in the appended claims.

Referring to the drawing, Fig. 1 is a perspective view of a tube socket constructed in accordance with my invention, Fig. .2 is an exploded vieWQof the socket illustrated in Fig. 1, Fig. 3 is a sctional view of the socket illustrated in Figs. 1 and 2 and showing a portion of a vacuu'm tube in operating position in the socket, and Fig. 4ris a 50 view similar to Fig. 3 but showing the socket before insertion of the tube terminals therein.

In theembodiment of theinvention illustrated in the drawing,y a supporting member I0, preferably entirely of insulating kmaterial in molded 55 form, is provided with openings ll arranged in any suitable manner about the center of the member and adapted to receive the terminalsVor contact pins or prongs l2, of a vacuum tube or like device the base I3 only of which is indicated in 60 the drawing. To provide detachable electrical connection between the tube terminals I2 and the various circuits in which the tube may be incorporated, substantially U-shaped contact members I4, preferably of strip bronze, are provided each having a bowed leg portion I5 disposed within one of the openings II and adapted to make resilient contact with one of the tube terminals I2, and a terminal portion I6 extending without the contact supporting member I0 for the attachment of suitable circuit leads. To form the openings lI the contact supporting member I0 is provided with relatively thin outer walls I and inner walls I8 between which are disposed resilient bowed contact portions I5 of contact members I4. To assist in retaining the contact members I 4 in proper position with respect to the supporting member or block I Ii before the insertion of the terminals I2 and to prevent the contact portions I5 from being forced out of the openings II by the terminals I2 asthe latter are inserted in the block, the portions I6 of these contact members extend across the upper ends IS of the outer walls I 'I and project outwardly of the member lil, these upper ends I9 being preferably rounded and the portions I6 of the contact members having bends or hook-like portions formed therein partially enclosing the ends of the thin walls I'I and preferably being correspondingly shaped to seat linnly upon the rounded portions of the walls.

In order to facilitate the operation of inserting` the tube terminals or prongs I2 in the socket and to assist in maintaining the tube in proper position after the insertion of the terminals, the inner walls I8 of the openings Il are each provided with a guiding surface 20 disposed centrally of the wall I8f This surface 20 is preferably semicylindrical in transverse section to conform to the surface of the tube terminal and extends a substantial distance parallel thereto. To insure sufficiently rm and at the-same time sufficiently exible electrical contact between terminals I2 and inner portions i5 of contact members or strips I4 and to assist in retaining the terminals in position in the socket, contact plates or tongues 2I are iprovided, preferably formed integrally with portions I5, the free ends of these contact plates or tongues being arranged to extend in the same direction as the free ends of the terminals I2 when the tube is in operative position in the socket. The contact plates 2| are so disposed and supported within the openings Il that upon insertion of the terminals I2 the free ends of the plates 2| are pressed toward the walls II on an arc of a circle having the 'end I 9 of the walls, i. e., the end thereof adjacent the base end of the terminals, substantially as a center. Upon vibration of the socket tending to'cause relative motion between a terminal and the free end of' a contact plate 2| the terminal tends to move or creep only in the direction of its freeend, or inwardly of the socket. This occurs by reason of the above-described. mounting of the contact plate whereby its free end tends to swing in an arc having a point near the base end of the terminal as its center. Upon vibration r.of the terminal and of the contact plate, the terminal may slide relatively freely in the direction away from the center of oscillation of the free end of the contact plate, whereas a wedging action of the contact line or edge of the plate against the surface of the terminal resists tendency of the terminal to move in a direction toward this center of oscillation of the free end of the contact plate.

Therefore with the contact plates 2l disposed as described herein with reference to their corresponding terminals I2, vibration of the socket tends to seat the terminals more firmly therein. The contact plates 2l may be formed from part 5 of a strip punched out centrally of the portions I5 of the contact members I 4, in such a 'manner' that relatively narrow strips 22 are left at the sides of portions I5, these strips 22 being so bent that when the contact members I4 are in posi- 10 tion in the socket ready to receive the prongs I2, the portions I 5 are in'contact at their extremities with the outer walls I and closely adjacent to or in contact with the inner walls I8 at a point intermediate their ends. Suitable clearance for l5 the contact plates 2l within the openings II may be provided by recesses 23 formed adjacent the semicylindrical surfaces 20 in the inner walls I8. To retain the contact members or strips I4 in position in the socket and to prevent the occur- 20 rence of short circuits when inserting the tube in the socket a second insulating member 24 of insulating material, preferably a plate, is provided having holes 25 for the passage of the terminals I2 therethrough, this plate extending a sub- 25 stantial distance beyond the periphery of vthe contact supporting member or block III. 'Ihe plate 24 may be fastened to the block I0 by a single rivet 25 disposed centrally thereof and the members 24 and Il! may be assembled in 30 proper radial position and prevented from turning with respect to each other by a lug 21 molded on block I0 and seating in a hole 28 formed in plate 24. When the perforated plate 24 is fastened to the contact supporting member I0, 35 the upper ends of the openings Il in this member I0 are closed by the plate and the contact portions I5 ofcontact members I4 are held in operative position in the socket and adjacent the walls of openings II ready for the contact plates 40 2| to be engaged by the tube terminals I2, the members I4 being disposed between the plate 24 and the upper ends I9 of the outer walls Il at a point on these members I4 intermediate the free ends thereof. As the prongs I2 are forced into 45 position against the contact plates 2I and tend to drive these plates downwardly, the contact members I4 are retained in position within the block I0 by the upper ends I9 of the walls I1,

over which the portions I6 of the contact mem- 50v bers pass.

In the assembly of the socket hereinbefore de-\ scribed, it will be observed that the contactmembers I4 are aligned in the socket between the walls II and I8 of the supporting member d5 I 0 and are retained securely in the socket by the insulating plate 24, no rivet or other fastening means being required to hold the contact strips in position other than the means for connecting the plate 24 to the member I0, which 60 may be merely the single rivet 26. When the socket is in position in the radio receiver ready for the insertion of the tube it is impossible to manipulate the tube in such a manner as to cause a short circuit due to the prongs I2 touching live 65 parts I4 of the socket, since these live parts are effectually separated from the tube side of the socket by the plate 24.

In inserting` the tube in the socket the prongs I2 are guided into position between tliesemi- 70 cylindrical portions 20 of inner walls I 8 and the resilient plates 2l connected to the portions I5 of the contact strips I4, and these portions I5y are pressed closely against the outer walls I1 of block I 0 as the plates 2I are forced outwardly 75 toward these outer walls with a wiping contact by the prongs, the disposition of the socket parts thus being such that no damage can result to the contact strips I4 if the attempt is made to insert the prongs at an angle to the center line of the openings After the tube is inserted in the socket and It will be noted further that a considerable latitude in the shape of the contact members I4 in the manufacture of a socket in accordance with my invention is possible, since the side strips 22 of contact portions I5 and the contact plates 2| are preferably bent initially before insertion' of contact members I4 in block I0 considerably more than is necessary to insure adequate electrical contact of plates 2| with the prongs |2, thus providing a large reserve of resiliency in these contact elements.

What I claim as new and desire to secure by Letters Patent of the United States, is:

1. In a socket for a vacuum tube or the like having a terminal prong, a contact supporting member having an opening relatively long axially of said member, a cover plate apertured for the passage of said prong into said opening, and a contact strip of thin, flexible and resilient conductive material, said strip having a bowed portion extending within said opening, one of the walls of said opening having a surface adapted to guide said prong into contact with said bowed strip portion, said bowed portion being maintained loosely laterally of said opening in position to make resilient contact with said prong, said bowed portion being between said wall and the wall opposite thereto of said opening, said strip having a hook portion bending over and extending across that end of said second-named wall which is adjacent said cover plate, said hook portion being maintained loosely in position be-f tween said second-named wall and said cover plate before said prong is inserted in sa1d socket.

2. In a socket for a vacuum tube or the like having a base and a terminal projecting from said base, a contact supporting member having an opening therein to receive the terminal, said member having a wall extendingalong a side of said opening a substantial distance parallel to said terminal, and a contact member having a portiony extending across an end of said wall adjacent the base end of said terminal to assist in holding the contact member loosely within the socket before the terminal is pressed thereinto and to prevent said contact member being pushed through the socket when the terminal is pressed into position therein, said contact member having a contact plate resiliently supported within said opening and extending substantially in the direction of the free end of said terminal, said contact plate having a free end abutting said terminal, said contact plate being so supported within said opening that upon insertion of the terminal in the socket said free end is pressed toward said wall on an arc of a circle having said 5 end of the wall substantially as a center, whereby upon vibration of said terminal and socket tending to cause slight relative motion therebetween a virtual ratchet action is produced between the contact plate and the terminal tending'to retain l0 the terminal in the socket.

3.. In a socket for a vacuum tube or the like having a base and a terminal projecting from said base, a contact supporting member having an opening therein to receive the terminaljV said 15 member having a wall extending along a side of said opening a substantial distance parallel to said terminal, and a 'contact member having a portion extending across an end of said wall adjacent the base end of said terminal to assist'20 in holding the contact member loosely withinthe socket before the terminal is pressed thereinto and to prevent said contact member being pushed through the socket when the terminal is pressed into position therein, said contact member hav- 25 ing a resilient portion adapted to be pressed into close contact at points adjacent its ends with said wall, said resilient portion having-a resilient con- *in 4the socket being pressed toward said wall on 35v y an arc of a`cirele having said end of the wall substantially as a center, whereby upon vibration of said terminal and socket tending to cause slight relative motion therebetween a virtual ratchet action is produced between the resilient contact 40 plate and the terminal tending to retain the ter- 'minal in the socket.

4. Ina socket for a vacuum tube or the like yhaving a base and a plurality of terminals projecting therefrom, a contact supporting mem- 45 ber of insulating material having a pluralityof f\ inner wall portions and outer wall portions defining openings in said supporting member to receive `the terminals, each of said inner walls having a terminal guiding surface, a plurality of `50 contact members each having a resilient portion extending within one of said openings, eachof said contact member portions including a resilient contact plate extending in the direction of the free end of the corresponding terminal and 55` having a free end abutting said corresponding terminal and pressed thereby toward the corresponding outer Wall' portion on an are of a circle having the end of said outer wall portion adja- DONALD R. DE TAR. 70 

